The sharing of flood waters in the Ksours of Ghardaia and Berriane (Algeria) hydraulic study

The present article deals with two systems of sharing flood waters used in the oases of Ghardaïa and Berriane. Based on bibliographic work, and data collection and investigations performed during the period between 2006 and 2018 near the Ksourian population as the floods are the only source of water for both oases. Ancestral hydraulic systems of sharing and regularizing floods were implemented in both oases. Each hydraulic system is composed of several hydraulic structures (e.g. dams, spillways, galleries, wells) that have been designed taking into considerations the geomorphology and topography of the region. This study compares the two systems and proves that although built 7 centuries ago, both the systems were built with intelligence. They have become parts of the national heritage and must be preserved for future generations

The Saoura foggaras : degradation of hydraulic system millennium Case of Beni Abbes, Oukda, Beni Ounif and Lahmar (Algeria)

In this article, we studied, for the first time, the foggaras of Saoura. Five missions were carried out in the oases of Kerzaz, Lahmar, Boukais, Beni Ounif, Ouakda, and Beni Abbes during the years 2009, 2010, 2011, 2012 and 2013. The first results showed that there was a difference between the foggaras of Touat and those of Saoura. The galleries of Saoura are much shorter than those of Touat and Gourara. On the contrary, the distribution of water from the Touat and Gourara foggaras is carried out per unit volume, whereas from the Saoura foggaras per unit time. The foggaras we visited are practically in a degraded condition. The contribution of modern technology (pumps and wells) in the oases of Saoura is the principal cause of the decline of the hydraulic system millennium

La foggara en Algérie : un patrimoine hydraulique mondial

Localisée dans les régions arides, la foggara en Algérie, le qanat en Iran, la khettara au Maroc et le falj au sultanat d’Oman constituent des procédés d’acquisition et de distribution d’eau, basé sur des galeries horizontales drainantes. Cependant, ces techniques traditionnelles, si elles présentent des similitudes au niveau du système de captage (galeries et puits), montrent des différences au niveau de la source de captage et de la technique de partage de l’eau.À travers cette étude, basée sur des sorties de prospection dans cinq oasis du Sahara algérien et des enquêtes menées au niveau des oasiens, on a pu recenser sept types de foggaras. Il s’agit de foggaras qui captent les eaux de la nappe phréatique au pied d’un djebel ou de la nappe du Continental Intercalaire, d’une source de la nappe du Grand Erg Occidental, de drainage et des infiltrations, et enfin, uniquement les eaux de crues (foggara de Mzab) ou drainent les eaux des oueds.Located in arid regions, the foggara in Algeria, the Qanat in Iran, Khettara in Morocco and Falj in Oman, are a system used for the acquisition and distribution of water, based on horizontal drainage galleries. However, although there are similarities in their collection system (galleries and shafts), these traditional techniques show differences in their water source and in the technique of water sharing. Through this study, based on prospecting trips in five oases of the Algerian Sahara and investigations at the oases, we could identify seven types of foggara, namely: those that receive water from the water table at the foot of a mountain range; those that drain the waters of the intermittent streams; which receive waters from the “Continental Intercalaire” aquifer; which receive water from a spring; which receive the waters from the Occidental Great Erg aquifer; which capture drainage and infiltration; and finally those that capture only flood waters (foggara of Mzab)

The foggara: a traditional system of irrigation in arid regions

This article discusses the traditional irrigation system in the oases of Touat, Gourara and Tidikelt. Since centuries, farmers use the system of foggaras for irrigation of palm groves and gardens. The results obtained following the inquiries and investigations carried out on the sites of foggaras, showed that since the eighties, drilling works multiplied in the oases of Touat, Gourara and Tidikelt. However, despite the application of these new techniques of water catchment, farmers still irrigate their gardens by traditional methods. For social, economic and environmental problems, foggaras degrade more and more; 50% of the foggaras decayed. Currently, the discharge of foggaras in service greatly diminished. The adoption of modern catchment techniques entails to the lowering of the water table

Silting of foum el gherza reservoir

The Foum El Gherza Reservoir fails to satisfy the irrigation of 300,000 palms of Sidi Okba and Seriana due to advanced siltation. Based on data from bathymetric surveys conducted by the National Agency for Dams, the siltation rate was estimated at 0.9 million m3/year. With a total capacity of 47 million of m3, the Foum El Gherza dam is silted up with more than 65 million m3. In this case, the life of the dam will not exceed 11 years of operation. The total silting of the reservoir will occur in 2023. Desilting the dam proves an emergency to save the palms of Seriana and Sidi Okba

Sediment Transport Modeling at the Oued Fodda Watershed Level Using HEC-RAS 1D Software

The objective of the current work is to determine the amount of sediments transported upstream and at the level of Oued Fodda dam. The latter is considered one of the first large dams built in Algeria. It’s exposed to a serious siltation problem that reduces its capacity every year. The simulation was executed using the HEC-RAS software, for the period varied from January 01, 2016 to April 30, 2016. The modeledsection consisted of about 9999 m length, subdivided into 141 river stations distant from each other by 70 m. The observation of the studied river section bed-profile was selected as a criterion for comparing the results of the model with the real values observed. A roughness coefficient of 0.031 was used. A quantitative estimate with a determination coefficient, R2, of 0.92 was used to support the validity. The mass and concentration of sediments increased significantly in the cross-sections located at the dam upstream.A total cumulative mass was estimated at approximately 712699 tons, just upstream of the dyke, and a maximum concentration of 22.35 g/l was observed, particularly for three main sections selected upstream of the Fodda wadi. However, at the reservoir level, the concentration variability is observed during flood periods, i.e., only for the most important flow

Extreme Rainfall-Runoff Events Modeling by HEC-HMS Model for Koudiet Rosfa Watershed, Algeria

Changing of precipitation regime and intensification of extreme storms in semi-arid regions because of climate change requires the use of numerical models to forecast the outlet hydrographs. In this paper, HEC-HMS software was applied using a loss method the curve number CN to estimate the precipitation excess and a parametric unit hydrograph model to compute the transformation of precipitation excess into direct runoff over the watershed. The Muskingum-Cunge routing model was used to simulate the propagation of direct runoff through the main streams of Koudiet Rosfa watershed. The curve number CN and lag time parameters were used to calibrate the model towards several storms. The Nash–Sutcliffe efficiency coefficient (NSE) was adopted to assess the performance of the model to reproduce the observed hydrographs. Volume of the storms, peak discharges, times of peak and times of center of mass between the simulated and observed discharges were used to validate the model. The simulated discharges reproduce the hydrological events. The calibrated model was used to simulate the different hypothetical storms that could occur in the future in order to ensure the safety of Koudiet Rosfa dam towards extreme rainfall-runoff events

Can be abandomed a traditional irrigation in the Quakda oasis (Algeria)?

Can we abandon traditional irrigation to the detriment of modern irrigation in the oasis of Ouakda? Is the question we posed in this study? Indeed, based on three missions carried out in the oasis of Ouakda during the years 2013, 2015 and 2016, we made visits and investigations to ancestral works as well as surveys of the local population. The results indicate that the Ksourian population irrigated the gardens and the palm grove by surface and underground water. Two ancestral dams made on the Bechar River for irrigation the gardens of the lower part. On the other hand, the foggaras irrigated the upper part of the palm grove. Today, new land has been built on the upper part of the palm grove. Thanks to new hydraulic techniques such as drilling and motor pumps, modern agriculture has developed on the other side of the palm grove to the detriment of oasis agriculture